PSY 2174 Lecture Notes - Lecture 15: Null Hypothesis, Statistical Hypothesis Testing, Alternative Hypothesis
19 Nov 2018
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States that there is no difference between the population means. Compare sample means to test the null hypothesis. Either reject or fail to reject the null hypothesis. Rejecting the null hypothesis suggests that there is a difference in the populations sampled. Failing to reject suggests that we don"t have evidence to suggest a difference exists. Alpha: the statistical decision criteria used in testing the null hypothesis. Traditionally, alpha is set to small values (0. 5 or 0. 1) Always a chance for error in our decision. In hypothesis testing, we"re testing whether or not a sample is likely to belong to a certain population that has a certain mean and sd. To say this formally, we set two hypotheses: Ha: the mean of the population our sample belongs to is the same as the mean of the population we"re comparing them to. You have a score that is likely to occur within that population, given its mean and standard deviation.
